Springs for automatic shutters



Jan. 1, 1957 H. s. MORRISON SPRINGS FOR AUTOMATIC SHUTTERS 2 Sheets-Sheet 1 Filed Feb. 15, 1954 FIG.

ATTORNEYS Jan. 1, 1957 H. s. MORRISON SPRINGS FOR AUTOMATIC SHUTTERS 2 Shets-Sheet 2 Filed Feb. 15, 1954 FIG. 2

FIG. 5

INVENTOR HUGH S. MORRISON BY \jzz qw wg ATTORNEYS 2,775,928 SPRINGS FOR AUTOMATIC SHUTTERS Hugh S. Morrison, Houston, Tex., assignor to Hackley Morrison,Jr., Houston, Tex.

Application February 15, 1954, Serial No. 410,403 4 Claims. (Cl. 98-419) This invention relates to attic ventilating equipment and more particularly to automatic shutters adapted to fit an opening in the ceiling. The present invention relates specifically to an automatic shutter of the general type illustrated in Patent No. 2,568,355, issued September 18, 1951, to Hackley Morrison.

As is well known, the ventilating fan is mounted in the attic above such a shutter, and the shutter doors, which are closed by gravity, are opened by the suction of the fan when it is in operation.

It has heretofore been proposed to provide tension springs in connection with a shutter of this general type, the purpose of such springs usually being to assist the suction of the fan in opening the shutter doors and to retard the closing movement of such doors under the influence of gravity so as to prevent them from slamming.

An object of the present invention is to devise an improved means for mounting such a spring so that it is accessible through one of the doors from below for adjusting the tension thereof.

Another object is to provide improved spring mounting means which will lie flat against the the shutter frame so that a plurality of such frames may be readily piled or stacked for shipment.

In order that the invention may be readily understood, reference is had to the accompanying drawings, forming part of this specification, and in which:

Fig. l is a fragmentary perspective view looking upward from below at one of the shutters, the doors being shown as partially open;

Fig. 2 is a plan view of the upper side of one of my improved shutters.

Fig. 3 is a longitudinal section substantially on the line 3-3 of Fig. 2 looking in the direction of the arrows,

Fig. 4 is a transverse section substantially on the line 44 of Fig. 2 looking in the direction of the arrows, and

Fig. 5 is a fragmentary side elevation of my improved spring mounting means, such means and the associated spring being illustrated in full and dotted lines in two different positions.

Referring to the drawings in detail the shuter comprises a rectangular frame made up of side bars 1, end bars 2, and cross bars 3. These bars may conveniently be in the form of upwardly opening channels as shown. The frame is made slightly larger than the opening in the ceiling A so that the side and end channels overlap the edges of the opening to constitute a trim, and the frame is secured in position as by means of screws C passing through the channels 1 and 2 and engaging in joists B as shown in Fig. 4.

Each of the side members of the frame also includes a relatively thin and deep structural element shown as in the form of an outwardly opening channel 4, set vertically and secured as by spot welding to the channel 1. This extends up inside of the ceiling opening, as shown in Fig. 4, and has a flat upper surface 4.

Extending between the channels 4 are hinge rods 5 on which the shutter doors 6 are mounted, preferably as by rolling the edge of the shutter around the rod as illustrated'in Fig. 3.

These doors are preferably formed of light sheet material such as aluminum, and the free edge of each door is bent upwardly as indicated at 7 in Fig. 3, and the upper edgesof the doors are rolled around transversely extending rods 8, as clearly shown. These rods 8 are pivot ally connected by one or more tie-bars 9, two such bars being shown in Fig. 2. Thus all of the doors open and close together, swinging about the rods 5. The doors move by gravity to the position shown in full lines in Fig. 3 and swing upwardly into open position, under the influence of the suction of the fan, as shown in Fig. 1, and in dotted lines in Fig. 3.

- My improved spring mounting means comprises a bracket 10 in the form of a relatively long, thin, narrow strip of metal, secured at one end as by welding to the upper flat face 4 of the channel 4, as clearly shown in Fig. 5. A tension spring 12 is connected at one end ice to the rod 8 at the free edge of one of the doors and. at the other end to the free end of the bracket or strip 10. Preferably one of these brackets and springs is provided at each side of the shutter frame as shown in:

Fig. 2.

My improved mounting bracket is made of material? stifi enough to sustain the pull of the spring, but flexible: enough to be manually bent as desired. When the frames: are shipped from the factory these strips lie flat against; the upper surface of the channels 4, as indicated in Fig. 3, and this permits a plurality of frames to be superposed or stacked. This makes it possible to pack a group of frames in a compact bundle for shipment.

After the shuter is installed on the ceiling as shown in Fig. 1 these bracket strips are accessible from below through one of the open shutter doors. The workman may then insert his hand up through such opening and manually bend the strip 10 upwardly as far as desired to give the proper tension to the spring, as indicated in full and dotted lines in Fig. 5.

The tension of the spring should, of course, be so adjusted that the doors will close gently without slamming, and will readily swing open when the fan starts.

What I claim is:

1. A ventilating shutter comprising a rectangular frame adapted to fit a ceiling opening and composed of side and end members, hinge rods extending between and supported by said side frame members, shutter doors carried at one edge on said hinge rods, means pivotally connecting the free edges of all of said doors, one of said side members having a portion formed with a fiat upper face, a bracket in the form of an elongated thin strip secured at one end to said fiat upper face and disposed at an acute angle thereto, and a tension spring connected at one end to the free end of said bracket and at the other end to the free edge of one of said doors.

2. A ventilating shutter comprising a rectangular frame adapted to fit a ceiling opening and composed of side and end members, hinge rods extending between and supported by said side frame members, shutter doors carried at one edge on said hinge rods, means pivotally connecting the free edges of all of said doors, one of said side members comprising a relatively deep and narrow structural element set vertically, a bracket in the form of a thin fiat strip secured at one end to the upper face of said structural member and lying in the same vertical plane at an acute angle thereto, and a tension spring connected at one end to the free end of said bracket and at the other end to the free edge of one of said doors.

3. A ventilating shutter comprising a rectangular frame adapted to fit a ceiling opening and composed of side and end members, hinge rods extending between and supported by said side frame members, shutter doors carried at one edge on said hinge rods, tie-bars pivotally connecting the free edges of all of said doors, one of said side members having a portion formedwith a flat upper face, a narrow, elongated bracket secured at one end.to said flat upperface, and atension spring'connected between, the free endof said bracket and the free edge of one of said doors, said bracket being sufiiciently rigid to sustain the pull of said spring, but bendable manually to various positions in a vertical plane to adjust the tension of said spring;

4. Aventilating shutter comprising a rectangular frame adapted tofit a ceiling opening and composed of side and end members, hinge rods extending-between and supportedby said side frame members,-shutter doors carried at one edge on said/hinge rods, tie-bars pivotally conmeeting the free edges of all ofsaid doors, one of said sidemernbers having a portion formed with a flat upper face, a narrow, elongated bracket secured at one end to said flat upper face, and a tension spring connected between the free end of said bracket and the free edge of one of said doors, said bracket being of relatively thin strip material and lying normally in substantial contact with said flat upper face, whereby a plurality of shutters may be superposed for shipment, and the free end of said bracket being manually bendable upwardly to any desired ex tentafter the shutter h as 'been installed.

Rferencs'Cit'edinthefile of this patent UNITED STATES PATENTS 2,191,774 

